The objectives of this open-label trial are to investigate the long-term safety and efficacy of lanreotide (IPSTYL) in the treatment of acromegaly by using normalization of GH and IGF-1 levels to guide dosing. Subjects must have been enrolled in a prior trial of IPSTYL. Secondary objectives are to investigate the efficacy and safety of IPSTYL in terms of tumor response, ability to control/reduce symptoms of acromegaly, adverse events and normalization of IGF-1 levels in a group of patients who have near normal levels.